Hearing devices provide amplified sound for the wearer. Some examples of hearing devices are headsets, hearing aids, in-ear monitors, cochlear implants, bone conduction devices, and personal listening devices. For example, hearing aids provide amplification to compensate for hearing loss by transmitting amplified sounds to the ear canals. Hearing devices can incorporate a radio coupled to an antenna. Antenna performance can vary significantly from one wearer to another, due to variations in head geometry, size, and material properties.